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On Wed, 17 Jan 2007, Michael Goodwin wrote:

> I have a question about 2a on this week's homework...
>
> I presume that "equivalent" means we want the Vout values to be the
> same.  This means that we want Vout in the second circuit to be 3.2V
> higher (relative to VEE) than the Vout of the first circuit (relative to
> VTT).  We know that Vout of the second circuit is VEE*R1/(R1+R2) since
> it's a voltage divider, but from there I am unclear as to what to do
> next.  I'll probably ask you about it after lecture today, but I thought
> I'd ask via email as well.  Thanks.
>
> --
> Michael P. Goodwin
> Aston Labs
> http://www.chem.purdue.edu/cooks

Date: Wed, 17 Jan 2007 13:52:03 -0500 (EST)
From: Timothy Matthew Jones <jones105@physics.purdue.edu>
To: Michael Goodwin <mgoodwin@purdue.edu>
Cc: mjones@physics.purdue.edu
Subject: Re: assignment 1

I'm not sure if I answered this in class or not but if not, I'll try
again.

If nothing was connected to the termination resistor, it would look like
a voltage source with a voltage of VTT and in impedance of 50 ohms.

So, you need to design a voltage divider, operating between 0 volts and
VEE=-5.2 volts, that looks like a voltage source with a voltage of VTT
under no load, and an impedance of 50 ohms.

Once you constructed the equivalent circuit, it the gate was connected to
V_out, it would behave the same way in each circuit.

So, if I understood what you wrote below, your understanding is correct,
but the explanation above might make it a bit more clear.

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On Wed, 17 Jan 2007, Samantha Merritt wrote:

> I have a question about the homework ... just a quick one.
>
> For problem one, when we are to calculate the cross sectional area,
> A, of the copper to get the resistivity of the various copper
> claddings... do we assume the cross sectional geometry to be
> rectangular or circular?  It seems that it would be essentially
> rectangular, but you used the word "diameter" in the question.  Maybe
> I'm confused.... how should I go about getting A?
>
> Samantha

Date: Wed, 17 Jan 2007 16:28:54 -0500 (EST)
From: Timothy Matthew Jones <jones105@physics.purdue.edu>
To: Samantha Merritt <merritss@purdue.edu>
Cc: mjones@physics.purdue.edu
Subject: Re: Question 1 (PHYS 536)

You're the second person to ask, and I have to admit that it isn't
entirely clear from the question.

You should assume the cross section is rectangular...  I should have used
'width' instead of 'diameter'.

I hope that helps.  Let me know if you have other questions.